scope:

This Standard covers gas infrastructure to and within multi-occupancy buildings including those designated as high risk buildings and the individual dwellings and commercial units within such buildings. The principles underpinning this Standard apply to all building situations whether typical or more complex ones (see Appendix 1).

Note: Properties deemed separate buildings, each comprising an individual single dwelling, such as detached, semi-detached or terraced houses/bungalows, are not covered by this Standard.

This Standard covers new, replacement and like for like component replacement of gas network pipelines, meter installations, installation pipework (including secondary meters), appliances and chimneys.

This Standard also covers inspection, maintenance, monitoring, repair, alteration and decommissioning processes.

Note 1: In this context, "new and replacement" embraces:

• any first time gas supply or replacement of any of the above mentioned sections of the gas supply system

• any new extension to an existing section of the gas supply system

• significant partial replacement of/alteration to any of the sections of the gas supply system. For example, the replacement of a riser system having one or more laterals connected would likely be deemed 'significant partial replacement'.

Regarding replacement/alteration, it is important to comply with legal obligations, for example, the checks required by Gas Safety (Installation & Use) Regulations (GS(I&U)R) following work on any part of a gas supply system.

Note 2: A network pipeline supplying a primary meter installation will be a "service" or a "distribution main". The difference, for the purposes of this Standard, is insignificant except when cross referring to other Standards, for example IGEM/TD/3 and IGEM/TD/4. This Standard uses either or both of the terms "network" or "pipeline" throughout.

Note 3: IGEM/TD/3 does not address pipes in buildings. IGEM/TD/4 references IGEM/G/5 with respect to gas in multi-occupancy buildings.

This Standard defines requirements covering the core areas of safety for gas in multi-occupancy buildings, such as:

• planning, risk assessment and minimising risk

• meter installations and location of gas meters with respect to escape routes and the GS(I&U)R and Building Regulations

Note: This affects many other aspects of the installation significantly, for example ventilation, consumer access for meter reading and isolation, and escape routes.

• network pipelines, types of building entry, risers, laterals and isolation valves

• ventilation of network pipelines, meter installations and installation pipework

• access for inspection and maintenance to network pipelines, meters, installation pipework and appliance chimneys

• modifications, repairs, testing, re-commissioning and decommissioning of existing network pipelines

• energy centres and their associated risks

• installation pipework, gas appliances and chimneys

• materials

• location of valves

• inspection, maintenance and decommissioning

• electrical safety and equipotential bonding.

Note: The text on this subject has been drawn up with the assistance of the Institution of Engineering Technology (IET) and the Energy Networks Association (ENA).

• roles, responsibilities and competence.

Note: This Standard includes requirements that are either additional to or vary existing requirements contained in other standards where the requirements of those other standards may not be sufficient for gas installations in multi-occupancy buildings. However, those existing Standards are referenced and the majority of their requirements will still apply where relevant. These standards include:

• IGEM/TD/3 and IGEM/TD/4 for network pipelines

• IGEM/TD/13 for pressure regulating installations (PRIs)

• BS 6400 for domestic-sized meter installations

• IGEM/GM/6 and IGEM/GM/8 for larger meter installations

• IGEM/GM/7A and IGEM/GM/7B for electrical connections to, and hazardous area classification of, meter installations

• BS 6891 for domestic-sized installation pipework

• IGEM/UP/2 for larger installation pipework

• IGE/UP/7 for timber and light steel framed buildings

• BS 5440-1 and 2 for the supply of chimneys and ventilation

• IGEM/UP/17 for dealing with shared chimney and flue systems

• BS 8313 Building Services in Ducts.

This Standard addresses requirements for the risk assessment of gas installations within any multi-occupancy building and the individual dwelling(s)/unit(s) within such a building.

This Standard generally addresses appliances within domestic dwellings or commercial units which have been UKCA or previously CE marked or designed to a relevant Standard.

This Standard covers all types of open flue chimney or room sealed chimney systems (that comply with appropriate construction standards) for gas appliances, whether they are separate from, or integral with, the appliances.

This Standard addresses gas installations intended to contain odorised Natural Gas (NG).

Note 1: This Standard assumes a gas supply layout as given in IGEM/G/1 for "Standard gas supply arrangements". Where a "bulk meter" serves secondary meters, via installation pipework, the principles of IGEM/UP/2 also may be applicable.

Note 2: For energy centre installations, see Section 11.

The term "meter" means "gas meter installation" unless otherwise stated.

The term Gas Transporter (GT) is deemed to include a "Gas Conveyor" conveying gas in a network pipeline.

Note 1: The definition of "Gas Conveyor" is given in IGEM/G/1 and IGEM/G/4.

Note 2: An alternative description taken from The Gas (Exemptions) Order 2011 is "Licence Exempt Gas Transporter".

All pressures quoted are gauge pressures, unless otherwise stated.

Italicised text is informative and does not represent formal requirements.

Appendices are informative and do not represent formal requirements unless specifically referenced in the main sections via the prescriptive terms "must", "shall" or "should".